So, here is the comment I posted :
as you may know, I'm a fervent Smashwords supporter, and will remain so. Still, this new service seems to me a little bit dodgy.
If I refer to the Publisher and Agent's doc, (http://www.smashwords.com/about/publisherdocs)you give roughly the same role to agents as you do to publishers.
I'm not sure it's in everyone's interest as it is right now.
I follow (along with a great number of self-publishers I think) closely a few blogs, among others that of Dean Wesley Smith, and of "The Passive Guy", and they BOTH concur on one point : if you have an agent, insit on "split" royalties and walk away if they don't allow that.
I think they have enough experience to grant them at least some consideration, and that you should allow that "split royalties" option in case some "agented" author wants to publish through Smashwords, but insists on split royalties.
One way to allow that would be, when a book is attached to both an author's account (no ghost) and an agent's one, for them to "fix" the "repartition". If both don't coincide, books sells are blocked .
Also, an author should have to approve a book's reassignment by the agent to an other author or ghost account before it takes effect.
Note also that this option could also help publishers by having the "royalties distribution" done at your level directly. If you don't want to allow that, a "lock" keeping an agent from switching to publisher if "split books are attached would also need to be implemented.
Of course, if the author doesn't have a real account, all the money should go to the agent, as is the case now.
Hope you don't mind (again) me giving my 2 cents and "criticizing" Smashwords, but at the moment, I don't think this new service is really on par with what you've accustomed us.